JPH0361581A - Method for printing fine pattern - Google Patents

Abstract

PURPOSE:To form a sharp pattern without generating a flow even when an image line groove is extremely fine by printing a required fine pattern on a substrate through an intaglio offset system using printing ink containing fine particles of pigment having specific particle size. CONSTITUTION:As the printing inks to be supplied to the image line grooves 31 of a printing plate, ink containing fine particles of pigments of three primary colors RGB each having particle size of 0.3mum or less is employed. Appropriate printing ink, for example, red printing ink R is supplied to the printing plate 3 and leveled by a squeeze and the excessive ink R is subsequently scraped off by a doctor 4 thus supplying the printing ink R to all of the image line grooves 31. A plate cylinder blanket 5 is brought into contact with the surface of the printing plate 3 under rotation to transfer the printing ink R. Further, the plate cylinder blanket 5 is brought into contact with the smooth surface 21 to be printed of a glass plate 2 to transfer the printing ink R, and an image line is successively formed by printing ink G, B.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a method for printing fine patterns,
In particular, the present invention relates to improvements in methods for printing fine patterns in electric or electronic components such as color filters used in liquid crystal color displays that require precision printing.

[Conventional technology]

Printing such fine patterns as described above requires extremely high precision; for example, in the case of color filters for liquid crystal color displays, continuous patterns of fine lines in the so-called RGB three primary colors of red, green, and blue are printed on a transparent glass substrate. The intaglio offset printing method is used to print on the paper. In this printing technique, the printing ink transferred from the printing plate to the plate cylinder blanket is transferred onto the glass substrate to be printed to obtain the required fine pattern. In recent years, there has been a growing demand for thinner and more precise filters.For example, in order to obtain high resolution, color filters used in liquid crystal color displays, for which demand has been increasing, have become increasingly necessary. There is a strong demand for fine patterns in which extremely thin lines of 60 μm are repeatedly formed. As the pattern becomes finer, it becomes difficult to evenly supply ink to the image grooves formed on the printing plate, which may cause the edges of the image to become unclear or the entire image to be dark and dark, making it difficult to print normally. There was a problem that it was difficult to do. Therefore,
In the current manufacturing process, a repair process is provided to improve product yield.

[Problem to be solved by the invention]

However, since the repair of fine patterns requires extremely detailed work that involves hand-painting while observing with a microscope, there is a problem in that the efficiency is not high compared to the amount of manual labor involved. Therefore, in order to fundamentally solve the problems of the prior art, the present invention aims to provide a printing means that does not generate defects in the process of forming fine patterns on a substrate.

[Means to solve the problem]

The present invention was made in order to solve the problems of the prior art described above, and it is a method of printing a required fine pattern on a substrate by an intaglio offset method using a printing ink consisting of fine particles of pigment of 0.3 μm or less. This is a fine pattern printing method characterized by the following.

[Effect]

According to the fine pattern printing method of the present invention, since the pigment in the printing ink is fine particles sized within a range of 0.3 μm or less, even if the image line on the printing plate is 50 μm wide,
Because it is sufficiently small, when the ink is spread on the printing plate and the excess is scraped off with a doctor, the printing ink remains in the printing groove in an extremely smooth and stable state. or,
Since sized resin and pigment are used, properties such as viscosity are constant, and even when printing ink is stably supplied to the printing groove and transferred to the plate cylinder blanket, a constant amount of printing ink is maintained at all times. is transferred and stable printing is performed.

【Example】

Next, the present invention will be explained in detail based on illustrated embodiments. This example is an example of manufacturing a color filter for use in a liquid crystal color display.
A fine pattern 1 consisting of three primary colors is printed on one smooth surface of the glass substrate 2. The fine pattern 1 is formed by repeatedly and continuously printing a striped red object r, a green object g1, and a blue object line, respectively, and the objects r1g and b are printed on one sheet. It is printed and formed by intaglio offset printing using the printing plate 3. The large number of image grooves 31 formed on the printing plate 3 are formed appropriately according to the specifications of the color filter to be the product, but in this case, in order to obtain the fine pattern 1, the grooves 31 are formed with a diameter of 50 μm.
, each with an interval twice the thickness, that is, 1
They are provided in parallel and spaced apart by 00 μm. The printing plate 3 is made by conventional means such as photolithography, which is well known to those skilled in the art, and the method of intaglio offset printing using the printing plate 3 is also well known to those skilled in the art. , groin explanation will be omitted, and only the constituent elements of the present invention will be described in detail.As the printing ink to be supplied to the printing groove 31 of the printing plate 3, RlG and H are shown in Table 1 for each of the RGB three-dimensional colors. The ink shown by the symbol is used, and in both cases, the pigment is sized into fine particles of 0.3 μm or less. Incidentally, the ink used conventionally has the same composition, and is a coarse printing ink with a pigment particle size of about 0.5 μm. Table 1 Appropriate printing ink, for example, red printing ink R, is supplied to the printing plate 3 having the above configuration, and after leveling it with a squeegee (not shown), the excess ink R is scraped off with a doctor 4, and all of the ink is removed. Printing ink R is supplied to the printing groove 31. Then, the plate cylinder blanket 5 is brought into contact with the surface of the printing plate 3 while rotating, and the printing ink R that has been supplied to the printing groove 31 is removed.
is transferred to the surface of the plate cylinder blanket 5. Further, the plate cylinder blanket 5 is placed on the smooth printing surface 21 of the glass substrate 2.
The drawing pattern of the printing plate 3 is transferred to the glass substrate 2 by rotating and contacting the printing ink R, but the doctor 4 slides on the surface of the printing plate 3,
When scraping off the excess printing ink R supplied to the printing ink R, the solid matter (resin and pigment) 6 is
Since the printing ink R is sized to be extremely fine particles, even from a microscopic point of view, the properties such as viscosity are stable, so that the printing ink R can be left uniformly in all the printing grooves 31. In this way, when intaglio offset printing is performed using the printing plate 3 in which a very constant amount of printing ink R is supplied to all of the printing grooves 31, a constant amount of printing ink R is always transferred to the plate cylinder blanket 5. Since the transfer to the glass substrate 2 is extremely stable, the red image line r with a width of 50 μm is printed vividly. After printing a large number of red print lines R continuously on the glass substrate 2 at intervals of 100 μm in this way, the printing plate 3 is shifted by 50 μm to the right side of the drawing and green printing ink G is applied onto the printing plate 3. Then, a drawing line is formed on the glass substrate 2 according to the same method. Furthermore, when the printing plate 3 is shifted by 50 μm in the same direction and a printing line is printed using blue printing ink B, a desired fine pattern L is obtained in which the RGB three primary color print lines rsg and b with a width of 50 μm are repeatedly printed. Glass substrate 2
is formed. The color filter in which the fine pattern 1 is printed and formed on one side of the glass substrate 2 by the above method is as follows:
As with conventional color filters, the printed surface is smoothed by polishing, rolling, etc., if necessary, and then electrodes are arranged and liquid crystal is filled in to create a liquid crystal color display. On the other hand, when the conventional printing ink R1 was used to form a red image r' on the glass substrate 2 by the above method, both ends of the image r' became unclear as shown in FIG. At the same time, defects such as pinhole-like white spots and shading occurred in the image r'. As shown in FIGS. 5 and 6, the reason why the image r' could not be printed neatly is that the solid matter 6, which is so large that it cannot be ignored in relation to the width and depth of the image structure 31, is in contact with the printing ink. Doctor 4 removes excess printing ink R1 because it is unevenly contained in R1.
This is thought to be due to the fact that the state of the printing ink remaining in the image line groove 31 is significantly different when a large solid object 6 is scraped off and when it is not written down. It should be noted that the fine pattern printing method of the present invention is not limited to the production of color filters used in liquid crystal color displays, but can be widely applied to printing and forming other general fine patterns. I would like to add.

【Effect of the invention】

As explained above, the fine pattern printing method according to the present invention uses a printing ink consisting of fine particles of pigment of 0.3μ or less to print a required fine pattern on a substrate by an intaglio offset method. Printing groove of plate 3 is 50μm
Even when the printing ink is extremely thin, a constant amount of printing ink is always stably supplied to all the printing grooves, so a clear fine pattern can be formed on glass substrates, etc. without any defects. Is possible. Therefore, the present invention can be applied to the production of recent liquid crystal color displays, etc., which require the formation of fine patterns, and has practical effects. 4. Brief explanation of the drawings Figure 1 is an explanatory diagram of the process of manufacturing a color filter by intaglio offset printing, Figure 2 is an enlarged explanatory diagram of the main part A1, Figure 3 is an enlarged explanatory diagram of the main part A2, FIG. 4 is an explanatory diagram of a color filter, and FIGS. 5 to 7 are explanatory diagrams of comparative examples. DESCRIPTION OF SYMBOLS 1... Fine pattern, 2... Glass substrate, 3... Printing plate, 31... Drawing groove, 4... Doctor 5... Plate cylinder blanket, rsglk)... Drawing line, RlGlB...Printing ink.

Claims (1)

[Claims] A method for printing a fine pattern, which comprises printing a desired fine pattern on a substrate by an intaglio offset method using a printing ink consisting of fine pigment particles of 0.3 μm or less.